All Questions
Tagged with distillation experimental-chemistry
23
questions
3
votes
1
answer
370
views
How can I read an Anschütz/Bennert manometer and how can I make sense of it?
Recently I have come across a mercury-filled manometer for vacuum distillation that somewhat resembles a U-tube shaped manometer, but with one arm sealed and completely filled with mercury. Searching ...
- 392
0
votes
0
answers
218
views
Can ethanol and heat during distillation cause degradation/dissolution of vinyl tubing leading hot vapors of the distillate to the condenser?
I'm a chemist and a qa lab, and we occasionally test herbal remedy products from one of our customers for alcohol content using a distillation, then using the specific gravity of the distillate to ...
- 1
1
vote
1
answer
358
views
Steam distillation vs fractional distillation
I am a high school student and I am a little confused in the techniques used to purify organic compounds. For example, in steam distillation we reduce the external pressure on the compound to be ...
- 252
1
vote
0
answers
44
views
Strange Distillation Behavior
I was attempting a fractional distillation with 1mL water and 1mL propylene glycol, and I’ve been encountering strange behavior with the heating of the mixture. The heating curve shows strange “spikes”...
- 102
7
votes
0
answers
200
views
Distilling milligram quantities of oil like it's late 1970s
In a currently retracted* manuscript by Tomas Hudlicky [1, Retraction Watch] the following has been noted:
Fifty years ago professors took an active part in all laboratory instructions and they ...
- 38.4k
1
vote
0
answers
49
views
How to handle CO2 being evolved during vacuum distillation?
Setup: vacuum aspirator pump, distillation apparatus with stirring (instead of a bubbler). Partial vacuum around 5" Hg.
What would you suggest to hold the vacuum set-point?
- 323
3
votes
1
answer
273
views
Separation of methanol–water mix in a plate distillation column
I conducted an experiment to separate methanol and water. I am trying to determine the mole fraction of the distillate collected but having a little trouble with the calculation.
The flow rate was $\...
- 31
0
votes
2
answers
457
views
Can you heat something at alcohol bath?
I have a mixture of $\ce{Et2O},$ $\ce{EtOH}$ and water, and I want to distill off the ether. I am using a water bath so not much water is distilled over, as the boiling water is 100 °C, and the ...
- 19
0
votes
1
answer
285
views
Why does steam distillation work?
I'm aware that there is a similar question here but it didn't really answer my specific questions.
I understand that steam distillation is used to separate an insoluble liquid from an aqueous solution,...
- 139
0
votes
1
answer
1k
views
Can I determine purity of isopropanol with a hydrometer?
Assuming I start with a known 99.8% purity of isopropanol, after recovery with a distillation apparatus, could I use a hydrometer to test for water content? If so, is there a special one I should use?
- 11
1
vote
2
answers
1k
views
At what position in the distillation apparatus does the temperature match the boiling point of the distilled substance?
A student is separating $\ce{CHCl3}$ (bp = $\pu{61 ^{\circ}C}$) from $\ce{CHCl2CHCl2}$ (bp = $\pu{146 ^{\circ}C}$) by distillation. She has just begun to collect the first distillate in the receiving ...
- 21
0
votes
1
answer
369
views
Last step of nicotine extraction using DCM
After using hydro-distillation method with distilled water and NaOH, separating the extract with dichloromethane, distillate it at 40 °C/104 °F, I'm left with some yellow pale oil.
I'm just wondering ...
3
votes
1
answer
3k
views
Isopropyl alcohol still leaves evaporation residue after distillation
I just finished distilling two liters of IPA because evaporating 5 ml on a watch glass revealed it to contain quite a bit of dissolved impurities. However, it still leaves some residue, even though I ...
- 101
6
votes
4
answers
548
views
To heat or not to heat; distillation?
One of the questions in a recent past paper I completed was:
One way to make water from the reservoir suitable for drinking is by distillation.
Describe how water is distilled.
And I answered ...
- 223
2
votes
1
answer
741
views
Distilling small volume
I have 50 ml of a compound I would like to purify. Since the impurities presents have close boiling points (b.p.), I have to use fractional distillation. Am I going to lose significant quantity of my ...
- 71